JPH05509143A - Flow control method and device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Flow control method and device The invention deals with turbocomponents that include both instabilities such as rotational stall and oscillation phenomena. Flow turbulence in the compressor, especially steady state or relates to methods and means for controlling metastable flow disturbances.

Rotational stall is an aerodynamic imbalance that determines the maximum pressure rise in a turbo compressor. Stability. At its maximum value, a large proportion of the annular cross section of the compressor led to the formation of less turbulent sections of flow (usually called cells) that spread quickly . Once the stop cell is fully formed, the outlet supply pressure from the compressor will quickly Fall. This type of flow disturbance is called a rotational stall. . This is because the disturbances or "blocked" sectors of the annulus flow are the It rotates with the wing approximately half way (typically between 0.8 and 0.3).

The compressor is located downstream of a large volume, for example in the pipeline of the combustion chamber of a gas turbine. The instability associated with the system of oscillations occurs when connected to the oscilloscope. Compress If the pressure increase capacity of the compressor is excessive and a stall condition is initialized, the A drop in supply pressure that causes the compressed gas in the downstream volume to backtrack through the compressor occurs. In extreme cases, flames may come out from the front of the engine. using this method By providing an outlet to the downstream volume, the stall condition dissipates and the downstream pressure is re-established. As the pressure rises, the downstream pressure can be increased. If the operating condition changes If not, the stalling, henching and refilling cycle will restart. Then a continuous sequence of surge cycles ensues.

This air is generated with surges and drains the boundary layer in the downstream region of the compressor. A method for detecting backflow back to the inlet is proposed in British Patent No. 1481031. . However, such a procedure may depend on established surge conditions for its operation. It's not enough.

Both stall and surge are damaging conditions that limit the operating range of the machine. Ru. The rotating stall brings the compressor to very high temperatures and places large bending loads on the blades. give. The way to avoid these dangers is to ensure that the compressor is in contact with its peak pressure. The goal is to ensure that it operates in such a way that it does not rise in the near future. However, recently It was suggested that active control techniques be used to improve performance. . UK patent 2191606A and AIAAr thrust and Nibstan, Fawkeswilliam and Gray in "Power Journal" Volume 2 No. 5 See ``Active Suppression of Instrumental Instabilities in Turbo Engines'' by Zurr. can be done.

In U.S. Pat. No. 4,196,472 (Radding et al.), a large number of The signal from the pressure transducer has a value related to the operating status within the compressor. A stall control system for an axial flow compressor is disclosed that compares a reference signal to . The signals from each transducer are sequentially compared to a reference signal, and one sensor When an outlier is detected by , corrective action is initiated. The signals are also summed and repaired. The strength of the positive effect is determined by the value of the summed signal. U.S. Patent No. 41964 The form of corrective action disclosed in No. 72 is based on the controllable It has been suggested that it takes the form of bleed and also controls the staggered angle of the stator blades.

At a series of circumferentially spaced locations in the direction of flow through the compressor Detection of rotational stalls and surges in turbo compressors to detect predetermined flow changes A new method to control such flow turbulence is proposed.

According to one aspect of the invention, when such a change is detected, the compressor A compressor downstream of the first region at a first axis station spaced from the outlet of the compressor. injecting a high pressure gas stream from a second axial station of the sensor. This injection A different variation of said variation to act on the flow turbulence directed by said variation. The direction of flow approximately in the selected manner in the circumferential direction depends on the starting point in the circumferential direction. directed towards.

According to another aspect of the invention, said changes at a series of said positions in a circumferential order Detection of the flow as directed by said change in an area remote from the compressor outlet Compress the gas flow at a pressure higher than the pressure in the injection area to operate against turbulence. It operates to inject into the tank.

A major feature of the invention, namely the use of propellant gas to counter flow turbulence, is the US Pat. No. 41964 where injection improves the basic surge margin of a compressor It has advantageous advantages over the method proposed by No. 72. Therefore, this combination can be operated at higher powers than with prior art bleed systems. .

Rotational stall conditions also occur in turbo compressors at low speeds and part load conditions.

In this case, it has been found that the instability occurs upstream of the compressor. The machine Since the early stages operate at a lower compression ratio than the optimum compression ratio, the It is designed to carry a relatively high load compared to the conventional one. compressor forward flow This will reach the string points and cause uncontrollable power losses. Also from the main light at the front of the turbo compressor in a manner similar to that described in high speed operation. This problem can be solved by injecting high pressure gas into the stage, preferably at the front stage. It can be used in opposition.

In a more general sense, the axial area of the compressor is selected for flow injection depending on the nature of the turbulence. Due to detected flow disturbances impact but to ensure adequate energy manpower to produce the greatest effect. In order to ensure that the injection pressure is sufficient at a location where the differential pressure is as low as possible, need to be guaranteed. If the flow is injected before the compressor, the compressor It is undesirable to collect air injected from the outlet of the sensor. Is it from an aerodynamic point of view? along the compressor flow path, each spanning only a small portion of that path. Although it is desirable to have continuous multiple flow injection circuits, the functionality of such a configuration Mechanical complexity is usually impractical.

Although it is sufficient to provide the detection and injection means at one axial station, the The provision of such means at a large number of stations is not precluded, as This is desirable. Practical methods for both fast and slow stalling are If there is tapping at the front, rear, and middle of the presser, this can be achieved with relatively simple means. in response to detection means in the intermediate region to counter high-speed stalls. Injects from the exit to the intermediate area and responds to detection means in the entry area to counter low speed spans This makes it possible to spray from the intermediate area to the front or entry area.

The main axial location at which flow turbulence begins is determined by different turbo compressor configurations. is expected to vary from meter to meter and by location of injection, and therefore the detection means Selected empirically. It is also independent of monitoring rotational stalls further upstream. The compressor flow should be monitored near its outlet for signs of a surge condition. There is.

It is possible to use any desired pattern of gas injection within the scope of the invention. . For example, in response to detecting a change in rotational flow, gas may be moved circumferentially at one station. is injected continuously through a series of ports with compensated intervals. Apart from that, gas are injected simultaneously through consecutive ports. a number of axially spaced at each station of gas injection means if the location has them, or other suitable It can be activated in response to a detected change in the location. Many control systems When used in axial locations, it can be operated independently of each location. Yes, or gas jets at different locations are operated in unison or in a predetermined order We will work together to make this happen.

In addition, the method of the present invention can deal with flow distortion when flow turbulence is not uniform in the circumferential direction. It can be used to This condition can occur during instantaneous operation or on an airplane. with respect to the engine axis at a greater angle than the normal flight path, such as occurs during takeoff of Occurs in aircraft when traveling at low speeds. The air intake area of the engine is Effectively “hidden” by the upstream engine cover, the compressor first stage flow It may be destroyed.

In this type of flow disturbance, signals from different stations work together to It is preferable to rely on sensors at several spaced axial locations, so that If multiple sensors at different locations at the same circumferential location provide operating signals, the gas Injection is triggered.

However, in order to prevent such static or relatively static flow disturbances, It is possible to rely on detection upstream of the compressor for this purpose. For example, When the sensor is operating in the engine compartment, the circumferential non-uniformity of the engine Appears in the engine room in front of the entrance. Within the scope of the invention, approximately the compressor To trigger the injection of gas supplied from further downstream of the compressor at the inlet Methods and means are provided for the detection of such flow turbulence for use in. this Such flow disturbances require fluid injection only on a portion of the periphery of the compressor.

According to another aspect of the invention, the direction of flow through the turbo compressor is selected. means for detecting changes in flow at a series of circumferentially spaced locations takes highly pressurized gas from a compressor downstream of said station and high pressure gas at said station or at a station adjacent thereto in this direction. means for re-injecting the compressor and for allowing said injection to occur; control means for detecting the detected change; actuating said control means in a selected manner circumferentially, thereby causing said change to occur; Therefore, it acts on the specified flow disturbance.

According to yet another aspect, a device for controlling gas flow in a turbocompressor is circumferential at a selected location axially in the direction of flow through the turbo compressor. means for detecting a change in flow at a series of locations spaced apart in the direction; To detect a change in flow greater than a predetermined change at each location from the signal from the detection means. and injecting high-pressure gas in the direction of flow, the pressure being higher than the pressure at said location. means for and in response to detecting said change at a series of said locations in a circumferential order; activating the injection means, thereby counteracting the flow turbulence appearing due to said change. and means for acting.

In the preferred method of operation, each valve controlling flow is activated when the jet stream is activated. and automatically closes again after a preset period of time. High pressure gas train This is because continuous injection is uneconomical. By gradually decreasing the initial flow, It is therefore preferable to do this so that the flow control effect is gradually removed. It will be done. Relatively long jet spacing is required to affect flow turbulence It is sometimes particularly applicable if flow turbulence appears before the flow is closed. The flow rate increases again towards the initial value. flow by tapering and restoring the flow. is kept to a minimum to control flow turbulence, eliminating the source of flow turbulence. I guarantee it will be shut down soon. Additionally, a timed taper of the jet stream energy to operate the system correctly without interfering with its effectiveness. Manpower can be limited. However, in certain flow systems, The on-off characteristics are equally effective and have the advantage of convenience. The preset interval If the flow turbulence remains after the elapsed time, the next injection interval is started immediately. Ma Additionally, the response of the system components ensures that the jet flow is unobstructed between the two intervals. Ru.

The control flow is gradually reduced without any control means using a feedback loop, but simply The present invention can be used regardless of whether or not the system is blocked. Gas injection begins corrective action can be initiated at maximum speed when a threshold level is exceeded. It is Noh. Then, if the jet stream is blocked or the jet velocity is reduced, the flow turbulence Complete correction at any stage if consecutive or restarted The effect is restored. This configuration allows for advance control without compromising the ability to control flow turbulence. Allows considerable simplification compared to the configuration of the technology. Also, if the operator It is very easy to provide manual actuation means that can operate the Become.

In a preferred control device of the present invention, each sensor signal includes a plurality of immediately preceding sensor signals. averaged by The average value is obtained and there is no difference between the instantaneous signal and the average signal. A signal is formed. If measurements of the relative magnitudes of different signals are made, then An operational output is created by detecting the relative magnitude of a signal above a certain level. . A series of operational outputs from multiple sensors actuates the injection means in a continuous pattern. It can be used to move.

The sampling period at a given rotation speed determines the maximum speed of response of the system . It can have a sampling period that occupies less than one revolution of the compressor. It is desirable and can be made in such a way that it is possible to do so. for example , three sensor outputs are required to obtain a given average signal, and six equiangular If there is a set of sensors placed: 1. /22 rotation rolling period is the operation output The average value and the instantaneous signal from one of these sensors determine whether can be used to compare the signals and obtain the average value from three consecutive sensors. Ru.

In the operation of the equipment, all circumferentially spaced or continuously operable output from several sensors indicates rotational stall, Simultaneous outputs from all or some of said sensors can detect surge conditions. show. In both cases, the gas injection process initialized as appropriate. In other words, the stall condition is caused by continuous gas in the peripheral direction. The injection port is opposed by the injection of the released.

In addition, all injection ports open simultaneously in response to rotational stall. It is now possible to do so. Although this is an uneconomical use of compressed air, It has the advantage of being particularly simple when only one valve is required.

Special equipment when responding to operational outputs from sensors in a circumferential sequence It is found to be suitable for adjusting continuous gas injections at different phases to suit the I know. However, this is usually not necessary (a typical trickle compressor In this case, the flow turbulence is usually assumed to be axial. Therefore, high pressure gas A gas ejection location axially coaxial with the location downstream of the tapping to supply gas. It is desirable to have one. If the rotational flow turbulence is suppressed, the circumference of the rotor Continuous operation of the gas injection will result in flow fluctuations at both the gas injection and gas suction locations. Acts against disturbances.

The flow through the injection location is controlled by each I-circle at an individual port or group of ports. controlled by By grouping ports, devices can be simplified. However, the amount of injection air required increases. To improve the turbulence of the jet flow Provides multiple orifice ports spread across a peripheral fan at each gas injection location It is preferable to do so.

Outlets must direct their flow towards the high pressure end of the compressor . In axial compressors, the outlet is in a plane less than 30° to the main flow line. Must be oriented at an angle in the radial plane of no more than 30° from the combresosa casing. Must be. The flow is circumferential in a diagonal direction that opposes the direction of rotation of the compressor. facing towards.

Also, for example, near the outlet of a high-speed compressor (as a manifestation of rotational stall) If the disturbance is more easily detected at stations downstream from its inception, then 1 It was found that one station could be used for operational signals. Also practically The detection means are connected to the gas injection so that their signals are not disturbed by the incoming gas. They should not be placed close to each other.

To further explain the invention, reference is made to the drawings.

Figures 1 to 3 show circumferentially spaced sections at the inlet end of an axial near compressor. 2 is a graph representing a series of simultaneous airflow measurements from a sensor;

FIG. 4 is a schematic diagram of an air compressor with flow control means according to the invention.

Figures 5-11 are diagrams of airflow measurements in a compressor that illustrate the operation of a fluid control device. Lot.

Figure 12 shows the characteristics of a compressor showing the performance improvements obtainable through the use of control means. This is a graph of gender.

FIG. 13 is a schematic diagram of a trickle jet engine with control means according to the invention.

Figures 14 and 15 schematically show the air injection means at the peripheral edge of the compressor casing. FIG.

Figure 15a is a modified detail view of the injection port.

FIG. 16 is a cross-sectional view of one form of control valve for jet flow.

17 and 18 are block diagrams showing details of the control device in FIG. 13. Ru.

FIG. 19 is another example of a trickle jet engine equipped with control means according to the invention .

Stall cells in axial compressors cannot detect flow disturbances for several milliseconds. Growth into a fully developed block was observed on the compressor rotor, approximately Occurs over 4 to 6 revolutions. This stall cell passes through the compressor It appears first at any point around the flow, and a series of spaced sensors detect this Necessary to detect stall cell initiation and development. Testing the basis of the invention The experiment is as shown in Figure 4 (actually less than half the chord upstream of the rotating disk). spaced circumferentially at an axial position immediately forward of the first rotating disc from the compressor casing by approximately 1/3 of the radial depth of the flow path. Turho compressor with a series of hot wire sensors located radially inward. This is done using a sa. For the consecutive experiments shown in Figures 1 to 3 and Figures 5 to 11. , simultaneous traces are plotted from a series of sensors with equal circumferential spacing. be done.

In Figure 1, the outputs from six circumferentially spaced hot wire sensors are As shown, the flow to the compressor is initially stable with a very low level of flow turbulence. The situation is as follows. Stall cells first appear as small flow disturbances that cause each It grows gradually as it passes through successive sensors, forming a V-shaped peak at A in the trace. It can be seen that it has a curve. Steady around the annular passage until the end of the third cycle It becomes a rotating, fully developed turbulence of the flow.

Through a similar series of traces, Figure 2 shows the onset of the surge cycle and the similar sequence as in Figure 1. It shows the time scale, and the first sign is the V-shaped stall that first appears in the trace. It is le. The continuous development after two rotations is very different from a rotational stall and all sections The output from the sensor simultaneously shows a relatively long drop in flow velocity. Actually shown in Figures 2 and 3. The first part of the surge cycle caused by 70-Refill” sequence. Slightly decreases as back pressure forms The stable flow that increases is eventually destroyed, the flow reverses, and the stable flow decreases again. It starts at high speed due to pressure. These experimental results show that stall and surge It begins with a small, sharply formed section of flow, but appears in the drawings shown. It should be understood that there is no need to exhibit a V-shaped profile. the system While this is true as a related phenomenon, surges can be caused by ” develops as instability.

FIG. 4 schematically shows a trickle compressor C equipped with flow control means according to the invention.

The hot wire sensor 2 connects the ring of the fixed guide hone 4 and the rotor plate. It can be seen between ring 6. Same axial location but circumferentially away from the sensor a series of air inlets 8 (only one of which is shown) arranged circumferentially at merge in a direction tangential to the inner wall 10 of the compressor casing. This input The entrance faces aft towards the adjacent rotor ring. The entrance is on the periphery The direction is set at a predetermined angle in the direction, and the direction is determined empirically, but preferably are oriented opposite the direction of rotation of the rotor. Entrance 8 is located at each first floor. Injection through the inlet by conduit 12 via shut-off valve 14 A similar arrangement is placed around the periphery of the high speed end of the compressor to provide high pressure air for It is connected to a series of conduits 18 leading from a number of separated tappings 20.

The valve 14 is normally closed, but a signal from the sensor 2 causes the control circuit 22 to Therefore, it is released. As further detailed below, at the compressor inlet If some or all sensors are louder than the expected level of noise in a steady flow. Detection of a flow turbulence by the compressor triggers the opening of valve 14, causing the compressor outlet to open. The high-pressure flow supplied from the rotor 6 is injected onto the first ring of the rotor 6.

In Figure 5, the output from a series of four equally spaced hot wire sensors is shown. First, a stall cell appears in the trace of sensor (2). stall cell When the flow circulates past sensors ■ and ■, the control circuit 22 determines that the flow disturbance the output from the control circuit is turned on to open valve 14. You can confirm that. Figure 5 shows how high-pressure compressed air flows Indicates whether the file is to be suppressed.

Figure 6 shows that by disabling the control unit and switching the valve closed, allows the stall cell to reappear, creating a fully developed rotating stall shape. shows the same configuration where the state quickly establishes itself.

In order to use high pressure air economically, the control unit 22 is installed in a stall. Once the cell is suppressed its valve must be closed. close the valve The use of a timer to determine the time is demonstrated in an experiment that generates the trace shown in FIG. stable flow The critical condition of the stall cell is detected by closing the valve after a short period of time. In each case, when the control system is activated, Flow turbulence is quickly removed. As shown by the trace in Figure 7 , the control system is switched after exhibiting its effect, at which time the next The reappearance of Roussel leads to a rotational stall condition.

FIGS. 8 and 9 show individual sensors operatively connected to circumferentially adjacent sensors. It operates to open each blowout valve and blows out high-pressure air through the inlet 8. Figure 7 shows an experiment similar to that of Figure 7 using a piezoelectric sensor that can be used.

Figure 8 shows how to suppress flow turbulence each time the first stall cell is detected. Show that. Figure 9 shows the opening and closing sequence of control valves controlling opposing flow injections. Indicates the As shown by several occurrences of traces ■ and ■, the control unit The cut is adjusted in response to sustained flow turbulence so that the effect of the valve opening period is extended. It can be arranged as shown below.

In Figure 10, a sensor trace recorded during a typical surge cycle is shown. , in which case the compressor in Figure 4 increases the pressure in the tank at the compressor outlet. supply its output to Stable condition due to compressor string After the initial flow turbulence of the state flow, the back flow from the tank will start normal steady flow. This cycle allows the outlet pressure to drop until the tank pressure is repeated as it rises to a critical level.

In Figure 11, the same surge cycle is shown in a compressed time interval and the control system system is switched over a period in the middle of the cycle. It's obvious In other words, the surge cycle is suppressed by operation of the injection valve and the control system is turned off. When you change, you will be taught again. The trace is one at the beginning of the first rotor stage. Shows the output from the hot wire sensor.

FIG. 12 shows typical pressure rise characteristics of an axial compressor. Do not use this invention. If the I will. When using the invention, the characteristic is determined by arrow B before breakdown occurs. It is extended to the point shown. A rapid conclusion of breakdown in actual performance The use of the present invention is difficult because of the need to operate with a large margin of safety depending on the The extension of operation provided by can produce real improvements in performance. Ru.

FIG. 13 has an axial compressor A, a combustion chamber C, and a turbine T. The gas turbine and the turbine are rotatably coupled together by a shaft S. This figure shows an application of the control device according to the present invention. The fluid sensor is mainly plate disc 1 The main sensor 102a to the front of the first stage of 06a and the sensor behind the stage near the high pressure outlet. Sensors 102b are located at two axial stations. Each station three or more equally spaced circumferentially around the casing in the There is a series of sensors 102.

The first series of injection ports 108a is located in the compressor case upstream of prestage 106a. around the sensor 102a but circumferentially spaced apart from the sensor 102a. con The first series of bleed ports 108a around the circumference of the intermediate stage of the presser are normally closed. When the valve 114a is opened, the injection port 108a enters the low pressure region. Allowing gas to flow through conduit 116. More bleedpaw A series of circumferentially disposed injection ports 1o8b adjacent to the conduit 110a 18, and also similarly positioned through normally closed valve 114b. High pressure gas can be received from the bleed port 110b. clearly This configuration of ports and valves is shown diametrically opposite, but below: As described in each having its own pair of valves 114a, 114b and a sector. Controls the flow through a series of injection and bleed ports located across the It has conduits 116 and 118.

The configuration shown in Figure 13 has two separate recirculations that can be operated independently of each other. provide the system. As shown, the valve 11 faces low force instability. The intermediate section passing through 4a to the recirculation section in the previous stage is connected to sensor 1 in the previous stage of the compressor. 02a by control circuit 202a in response to signals from 02a. Valve 11 Recirculation from the rear to the intermediate stage through 4b is provided by a sensor near the rear of the compressor. It is adjusted by the control circuit 202b according to the signal from the sensor 102b. control circuit Other details of 202 are described with reference to FIGS. 17 and 18.

14 and 15 illustrate the air injection structure in further detail with a typical port 108.

This port is mounted on the inner wall 124 of the axial compressor casing. located within one ring of the guide vanes. Each port has plenum 12 8 into the gas flow passage of the compressor. 4. This nozzle is inclined by 30 degrees in the axial direction, and the injected air ■ is directed into the mainstream F. It is designed to flow diagonally at the shallowest possible radial angle. large number of nozzles helps keep the radial injection angle small by splitting the flow through the do. A lip 130 is attached to each nozzle to assist in limiting the radial spray angle. It covers the edge of the exit. Further, this nozzle 126 is inclined in the circumferential direction. so that the flow through them resists the rotational component of the main flow through the guide vanes. The jet is injected with several rotational components in the direction of rotation.

FIG. 15a shows the trailing edge of the stator guide vane 122 and the leading edge of the rotor blade 123. Another location of the port 126 is shown in the axial gap between. Shown in Figure 15a The advantage of this configuration is that the jet periphery angle is limited by the proximity of the stator guide vanes. This means that they can change more freely because they can't do anything. This angle is wide It varies within a wide range, but it is approximately equal to the stagger angle of the rotor blades of the adjacent ring in the axial direction. It is preferable that the angle be between the two directions.

This port 108 is located between each successive pair of guide vanes 122 and is located between each planar l , to supply injection air to a 60° sector around the periphery of the compressor. It is connected to a series of Blenheims 128. Each 60° sector has its own control a corresponding 60° sector extension at the downstream station with valve 114; 110. In each sector of 60°, preferably an injection port and one fluid sensor 102 at approximately the same axial station, or circumferentially It has a plurality of spaced apart sensors. Sensor 102 is preferably as shown in FIG. It is a static sensor mounted at the same height inside the casing. flow Preferred form of valve 114 for reasonably rapid response to detection of disturbances in The situation is shown in FIG. Casing 14 via upper and lower bearings 148,150 6 has a rotor 142 mounted on a spindle 144. Rotor 14 2 is a hollow cylinder that is tightly fixed but free inside the cylindrical stator 152. Slidable. Both the rotor and stator have a series of slots within the cylindrical wall. However, the two successive throws are moved by a relatively small rotational movement of the rotor. It is possible to prevent the data from being aligned. Throttles that do not match the flow through the valve The cut will be blocked. inside the valve casing 146 when the slots are aligned. The gas from the supply conduit 156 reaching the circulation chamber 158 passes through the slot. , over the spider 159 supporting the lower bearing 150 and through the valve outlet 160. can flow. To achieve quick switching, the valve rotor is For example, it has a lightweight structure made of carbon composite material. This stator has a wide fixed preferably manufactured from the same material so that it is maintained over a wide range of temperatures. stomach.

Movement of the valve is coupled to an electromagnet 164 and rotor 142 fixed within the casing. electromagnetically controlled by a torque motor 162 having an armature 166 attached. It will be done. This motor requires a mechanical stop mechanism to place the rotor in both positions. Can be moved between positions corresponding to the open and closed states of the valve to prevent It is.

The portions of the control circuit 202 associated with the outputs of the individual sensors are further shown in FIGS. 17 and 18. Shown in detail. As shown in Figure 17, the electrical signals from each sensor output are first filtered in a low-pass filter 210 to remove turbulence in the flow of the The filtered signal is then processed in an integrator 212. The integrator has at least three consecutive The average sensor over a rolling period equal to the sampling of sensors 102 For example, if there is one sensor per fan, then 1/2 Small enough to rotate. The average value provides a stable but continuously updated base level; instantaneous changes can be measured with respect to a baseline level.

The integrated output C is compared with the filtered instantaneous signal S in a subtraction unit 214. , the difference d between the two signals is the perturbation, and the instant from the average of the rolling signal divergence. The division circuit 216 calculates the ratio of the current average value C. -calculate the ratio of deflections d and obtain a non-dimensional measure of deflection e. Ru. The output e from the divider circuit 216 will be at least equal to must also be aligned with the preset level is also supplied to the first discriminator 218 . The output f from this discriminator is the size of the division is on if equal to or greater than X. Preset flow turbulence manipulation The work level X is selected to be the value that appears in the stall condition.

The signals and outputs f obtained from the individual sensors are each connected to each valve 114. is used to operate an array of AND gates 219-219n.

Each valve has its AND gate output f and the sensor associated circumferentially with that valve. It is opened when both signals from the sensor are received, and operates the relay 220 of the valve. generates output. Each of the valves therefore has a signal that generates a flow turbulence output f. They are sequentially opened in accordance with the peripheral position of the detected flow signal when the flow signal is detected. should be released The valve is located in the same segment as the compressor air passage when a flow turbulence is detected. lubricant or a fan following the direction of rotation if necessary to compensate for response delays. Ru.

Another separator 218' in the circuit of FIG. 18 receives the signal e and outputs it at level X'. f', the level X' is adjusted in response to normal engine operation such as acceleration and deceleration. greater than the value that appears in the condition, but below the level that appears in the stall condition. this is For example, it is used to counter flow turbulence in extreme flight positions.

Additional and/or other methods of providing the necessary recirculation flow are shown in Figure 18. This is accomplished by processing f or fo. In the circuit of FIG. The device 222 uses the output from the separator 218 for all sensors in each stage to It has address 223. When the output f (e>x) is generated, the signal is This is maintained at least during the rolling period of the compressor 212. Inside the storage device The value held in is retrieved in the step of operating address 223, It is summed in an additional circuit 224 for all sensors in that membrane. comparison The controller 228 determines whether the summed signal exceeds a predetermined value and controls the valve. Circuit 232 connects the injection valve or valve 11 to the appropriate compressor location. It operates to open 4. At the same time, the timer 234 starts again after a predetermined period of time. 114 and one or two revolutions of the compressor do.

port 110a by multiple stages of flow sensors between these two sets of ports. If it is desired to monitor the need for recirculation flow such as port 108a from , the circuit of Figure 18 is for different stages of sensors but similar peripheral positions, respectively. Expanded by including additional circuitry 226. These signals are rotational stalls If they exist, they are expected to reinforce each other. Comparator 230 adds signal is predetermined to open valve control circuit 232 as previously described. Determine whether the value of is exceeded.

Figure 19 shows an isolation valve similar to valve 114 but designed for three-way operation. 2 shows a gas turbine with a device according to the invention having a valve 250; Each bar The tab 250 has three positions. That is, it is (i) a conduit communicating with the valve; (ii) conduit 252.252.254 and 256 are isolated from each other in the closed position; a first operating state in which the conduits 254 are connected to each other and the conduits 256 remain blocked; (ml) Conduits 254, 256 are connected to each other and conduit 252 is blocked in the second There are three positions in the working state. The illustrated valve 250 and its associated conduit are empty. control to draw in air and supply it to the nozzle ring at the selected takeoff and injection stages. Only one of a series of air circulation devices spaced around the periphery of the show.

The control system shown in FIG. ．． Inlet temperature sensor 262 provides input to operating unit 270 via 268 and an axis speed sensor 264. This unit 270 acts on the input and modifies it. produces an output N/T representing the flow conditions in the compressor. do.

The processing unit 280 controls the valve 250 to create a fixed period of air injection. The unit is activated by a signal from a static pressure sensor that indicates a flow disturbance that triggers the opening of the operates in the manner already described above with reference to page 202. However, an additional N/ The lower value indicates that the output from the unit 280 is the path 254, 252 or the path 256°. 254 to determine whether to operate valve 250 to open valve 254. It is input to processor 280. A low value of N/T means downward power operation of the compressor. valve 250 allows air taken from the intermediate station to pass through conduit 252. The fuel is then injected into the front of the compressor. A high value of N/T means that the flow Indicates that correction is required in the downstream membrane when a turbulence occurs, and valve 250 so that air from the compressor outlet is injected into the intermediate stage via conduit 254. Open. For motion control systems, linear feedback is provided within the system described above. It should be noted that there is no lock control. This considerably simplifies the control system. simply done. Detection of flow disturbances exceeding a predetermined value will result in a fixed response (response Possibilities for other forms of response are available for other forms of flow turbulence). This process Valid even if movement is required to be measurable before the response is initialized It turns out that it is possible to perform certain actions. If flow turbulence exists, this The system can also provide fixed responses.

Furthermore, the control method according to the present invention does not necessarily cause distortion of the stable flow; A circumferential direction in the flow that does not lead to abrupt changes, but reduces the performance of the turbo compressor. It operates to counteract the imbalance of components in one direction. For this purpose, specific locations and sectors when constant flow distortion is indicated by the detected signal. to act on the appropriate one injection valve or selected group of valves. Placed.

time (ms) time (ms) time (ms) time (ms) Pressure rise coefficient (ΔP/PLJ2) abstract The present invention provides at least one selected station in the direction of flow through the compressor. A trickle compressor where the flow of fluid is detected at a series of circumferentially spaced locations. A method for controlling gas flow within a sensor (C) is provided. Changes in flow above a predetermined limit are to provide an operational response if flow turbulence above a predetermined acceptable level is detected. be evaluated. When such flow disturbances are detected, the supply from further downstream is High pressure gas is injected at said station to provide the main gas flow. rotate Stall cells appear as continuous changes occurring at circumferentially spaced locations. .

Complete flow turbulence by responding to such conditions by compressed jet flow Suppresses both rotational stall and surge conditions in the compressor before they develop I found out that it is possible. The same means are deployed to counter steady-state distortions. can be placed.

Submission of translation of written amendment (Article 184-8 of the Patent Act) February 11, 1993

Claims (31)

[Claims] 1. Perimeter of selected axial stations in the direction of flow through the compressor Detects changes in the flow above a given change limit at -ream locations spaced apart in the direction. , high pressure gas from the downstream area of said selected location when detecting such change. in the direction of said flow and in the circumferential direction by the circumferential starting point of said change. inject into said area in a manner selected to cause a disturbance in the flow directed by said change. A method of controlling gas flow in a turbo compressor that is opposed to. 2. Perimeter of selected axial stations in the direction of flow through the compressor Detect flow at a series of locations spaced apart in the direction to detect flow above a predetermined change limit. detecting a change, and detecting the change at the location of the series in a circumferential order; injecting a gas stream at a high pressure greater than the station pressure as directed by said change. The flow acts on the turbulence of the flow, and the flow is driven by a jet jet that injects substantially in the direction of the flow. How to control gas flow in a Bocompressor. 3. Claim 1 or 2, wherein after a fixed period of time an operation is performed to terminate the flow. The method described in. 4. 4. The pressure jet flow gradually decreases after its initiation. The method described in. 5. 5. The pressure jet flow according to claim 1, wherein the pressure jet flow is interrupted after a predetermined time. How to put it on. 6. Flow changes occur at multiple stations spaced from each other in the flow direction. detected, and said injection of high pressure gas is responsive to said change detection at said station. Any one of claims 1 to 5, which is carried out at or adjacent to each of the stations. The method described in paragraph 1. 7. The change in flow occurs at least at a first location adjacent to the compressor inlet; A high pressure flow is detected at a second location intermediate the flow path through which the high pressure flow is directed to each said station. The high pressure gas flow at the first station is injected into the second station. The high pressure gas flow at the second station is supplied from the second station. 7. The method of claim 6, wherein the method is fed from downstream of the pump. 8. The flow injection is carried out in different fans around the periphery of the turbo compressor. wherein the flow is detected independently in each of the sectors. 7. The method according to any one of Items 7 to 9. 9. Claim in which the supply of high pressure is taken from the same fan as the same fan from which it was injected. 8. The method described in 8. 10. the detected signal of the change at each of the spaced apart locations of the station; is a rolling interval corresponding to flow detection at at least three circumferentially consecutive locations. 2. The method of claim 1, wherein the turbulence of the flow is averaged over an interval to provide an average value of the series. 9. The method according to any one of 9. 11. A difference signal is formed between the detected signal and the intermediate signal, and the relative magnitude of the difference signal is determined. the relative magnitude of the difference signal from each of the multiple detection locations above a predetermined level. The detection of the pressure creates a relative output to activate the pressure jet flow. 11. The method according to claim 10. 12. Activation of the pressure jet flow is performed at a small number of locations spaced circumferentially from one said location. so as to continuously detect changes in the flow above a predetermined limit in at least some of the 2. The method of claim 1, wherein the method is adapted to operate. 13. 2. The direction of injection is at a radial angle of substantially no more than 30°. 13. The method according to any one of 1 to 12. 14. The direction of injection has a circumferential component opposite to the direction of the compressor rotor. 14. Any one of claims 1 to 13 for controlling the flow in an axial compressor. The method described in paragraph (1). 15. Claim 1: The predetermined limit of flow change is not less than 2% of the average flow detected. 14. The method according to any one of 13 to 13. 16. Variation of flow in one way with respect to each other at a series of circumferentially spaced locations The flow through the compressor is approximately a peripheral area in which a change is detected from a downstream area of the location in the direction of and the detection position; Gas flow in a turbo compressor that injects a high pressure gas flow into the same area as the flow direction How to control. 17. a series of circumferentially spaced locations and in the direction of flow through the compressor. means for detecting changes in the flow at a selected axial location; means for supplying high pressure gas from an area downstream of the location; Inject high pressure gas into the compressor at or adjacent to the selected location. and means for acting on the disturbances in the flow directed by said change. , controlled in a selected manner circumferentially by the circumferential starting point of the detected change. a detection device for activating the means for selecting the gas flow in the turbo compressor; equipment for. 18. a series of circumferentially spaced locations and in the direction of flow through the compressor. means for detecting changes in the flow at selected axial locations; To detect a change in flow above a predetermined change limit from the signal from the location detection means. and for injecting a gas stream at a pressure substantially higher than the pressure in the direction of flow at said location. and in response to the detection of the change in the circumferential direction of the plurality of locations; activating the means thereby acting against the flow disturbance indicated by said change; and means for activating the injection means to use the turbo compressor. device for controlling the gas flow of. 19. the detection means are provided at a plurality of locations spaced apart from each other in the flow direction; the injector is provided at or adjacent to each station; The control means controls each station in response to detecting a change in flow at the station. 19. A device according to claim 17 or 18, adapted to initiate the jet stream at a . 20. The station is a first station adjacent to the inlet of the compressor. a second station intermediate the flow path therethrough; flow injection means at or adjacent to said intermediate station; a first station having means for communicating with the main compressor flow adjacent thereto; a first conduit means for providing flow injection to said second downstream main compressor; a second station having flow means for communicating with the flow; 20. A device according to claim 19, further comprising second conduit means for said second conduit means. 21. A common valve means is provided for blocking said jet flow or for said conduit means. Claim 2 provided for allowing flow through either 0. 22. 22. The flow control means according to claim 17 or 21, wherein the flow control means is biased to a normally closed position. The means described in any one of the paragraphs. 23. A supply means and an injection means in each of the peripheral fans of the compressor. and each detection means is provided in the fan-shaped portion, and each control means is arranged in each of the fan-shaped portions. claim 17, wherein the detection means is actuable by means of a detection means capable of individually effecting a flow injection. 23. The apparatus according to any one of et al. 24. 24. The device of claim 23, having at least six said sectors. 25. The fluid ejection means has an outlet oriented at a radial angle not greater than 30°. 25. A device according to any one of claims 17 to 24. 26. The outlet is such that the injection portion of each nozzle outlet deflects the nozzle outlet in a downstream direction. 26. The device of claim 25, comprising a nozzle. 27. The control means includes a cylindrical stator and a cylindrical stator that is slidably and tightly fitted into the stator. Has mating cylindrical rotors, each stake and each rotor opening and closing a valve spaced circumferentially of the reams so as to be aligned or disengaged by rotation of the rotor. 27. A device according to claims 17 to 26, having spaced apertures. 28. 28. The electromagnetic drive means determines each location of rotational movement of the rotor. equipment. 29. having means for reducing or stopping said jet stream at predetermined time intervals; 29. Apparatus according to any one of claims 17 to 28. 30. The control means is adapted to detect flow disturbances in order to obtain an average value of the series. During the rolling period corresponding to the flow detection time at three consecutive locations in the circumferential direction. means for averaging the signals detected at said spaced locations over the 30. Means according to any one of claims 17 to 29. 31. Means for forming a difference signal between the instantaneously detected signal and the average signal and a means for measuring the relative magnitude of the difference signal; To generate a pressure jet activation signal upon detection of a relative magnitude above a certain level. 31. The apparatus according to claim 30, comprising output means for.